The present invention is directed generally to a fluid supply assembly for a fluid applicator, and more particularly to a fluid supply assembly having an improved seal between a disposable cup and a disposable lid.
Some fluid applicators, such as gravity feed paint spray guns, have a fluid supply cup mounted on top of the fluid applicator. The fluid supply cup is typically reusable. Fluid, such as paint, is generally measured and mixed in a separate container, and then poured into the fluid supply cup for use. The container for measuring and mixing must be either cleaned or disposed of. During fluid application, the user must be careful not to tip the fluid applicator too much, or fluid will leak out a vent in the fluid supply cup. In addition, the user cannot use all of the fluid because it moves around in the fluid supply cup and air can be drawn into the drain hole.
Attempts have been made to provide fluid supply assemblies which do not leak during use. For example, U.S. Pat. No. 5,582,350 describes a hand held spray gun with a top mounted paint cup which extends from the rear of the gun body at an angle of 30°±10°. The paint can be sealed in a collapsible closed bag in the paint cup, eliminating the need for a vent. Using the closed bag, the gun can be operated at all angles without the paint leaking out of the vent in the paint cup. The use of the closed bag also allows more of the paint to be used. In addition, it reduces cleanup time and cost because the bag keeps the paint cup clean. Thus, U.S. Pat. No. 5,582,350 represented a significant advance in the art.
U.S. Pat. No. 6,588,681 describes a paint cup with an outer container and an inner liner. There is an indicating sheet with indicia for measuring the paint components which must be positioned carefully between the inner liner and the outer container so that the indicia for measuring are aligned accurately. The paint cup includes a lid which is sealed to the outer container with an external sealing ring. An additional support ring is required so that the paint cup can be used on a paint shaker machine. Moreover, the paint cup is unnecessarily complicated.